1. Field of the Invention
This application relates to an imaging apparatus and an imaging method.
2. Description of the Related Art
In the photographing using an imaging apparatus such as a digital camera, a bright scene may be photographed at a low shutter-release speed or a plurality of objects at different distances may be photographed, all in focused state. In this case, the F number is be increased (thus reducing the aperture of the diaphragm), or the depth of focus is increased. If the F number or the depth of focus is increased, however, the modulation transfer function (MTF) of the lens will degrade by diffraction, ultimately rendering the resultant image unclear.
In this regard, Jpn. Pat. Appln. KOKAI Publication No. 2004-146993 discloses a recording apparatus, which uses a neutral density (ND) filter to lower the exposure. The diffraction is thus suppressed in this recording apparatus, preventing a large degradation of the lens MTF. In this recording apparatus, the image signal is corrected in accordance with the aperture set to the apparatus, thereby compensating for the resolution decrease resulting from the change in the lens MTF.